This invention relates generally to new and improved apparatus for providing the internal portion of tubing with at least one internal spiral fin and more particularly is an improvement of the invention disclosed in U.S. Pat. No. 4,702,096 issued Oct. 27, 1987 to Francis J. Fuchs, Jr., entitled APPARATUS AND PROCESS FOR PROVIDING TUBING WITH AT LEAST ONE INTERNAL SPIRAL GROOVE OR FIN; this patent is hereby incorporated herein by reference as if fully set forth herein and will be referred to hereinafter as the "Fuchs '096 Patent." Accordingly, it will be understood that the apparatus of this invention is for the same purpose as the apparatus disclosed in the Fuchs '096 Patent and for overcoming the same prior art problems taught in the BACKGROUND OF THE INVENTION of the Fuchs '096 Patent.
As will be better understood from the detailed description of the present invention set forth below, the apparatus of the present invention is shorter and more compact than the apparatus of the Fuchs '096 Patent, particularly that shown in FIGS. 7 and 8, and unlike the apparatus of the Fuchs '096 Patent the multi-stage ball bearing assembly of the present invention extends inwardly of, instead of outwardly from, the floating plug or forward portion of the mandrel to which the assembly is mounted thereby making the assembly less subject to damage and axial misalignment. Also, it has been found that mounting the multi-stage ball bearing assembly inwardly of the floating plug or forward portion of the mandrel makes the removal and replacement of the spinner easier, less time consuming and therefore more efficient to maintain.